remove crt's "this function or variable may be unsafe" warnings

they are useless, as they are in dependencies or parts of the code
we don't care about. Also, the "safe" alternatives straightup dont work
on linux.

CMakeLists.txt

@@ -139,6 +139,7 @@ set(BeamMP_Includes
 
 set(BeamMP_Definitions
     SECRET_SENTRY_URL="${BEAMMP_SECRET_SENTRY_URL}"
+    _CRT_SECURE_NO_WARNINGS
 )
 
 if (UNIX)